Title: Broiler litter application and tillage effects on restoration of degraded soils Authors
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 12, 2009
Publication Date: N/A
Interpretive Summary: Improper soil management and crop production have resulted in soil quality degradation leading to soil organic matter losses affecting water and nutrient availability and consequently plant growth. Many soils in Mississippi were degraded by erosion and nutrient depletion when they were row-cropped with intensive cultivation years ago. Degraded soils decrease plant yield through increased bulk density, reduced organic matter content, nutrient availability, and water-holding capacity. Land degradation is one of the major environmental concerns not only by the production of food but also by the maintenance of environmental quality. Permanent reduction in crop productivity of degraded soils is caused by changes in physical, chemical, and biological properties mainly resulting from losses of carbon by either oxidation from intensive cultivation or through erosion. Since organic matter is one of the most chemically active components in the soil and serves as a reservoir for holding nutrients, reduced organic matter in degraded soils results in a greater potential for leaching of nutrients which leads to a decline in soil fertility and productivity. To overcome this problem, nutrient management strategies are needed to provide available nutrient and organic matter for plant growth and to improve soil physical condition. Substantial studies have been carried out on the application of organic wastes for improvement of soil physiochemical and biological properties and enhancement of crop production under different soil management systems. However, not much attention has been devoted to determine the effects of long-term broiler litter application on the restoration quality of degraded soil. The objective of this study was to determine the effects of broiler litter application and soil management practices on selected soil physiochemical and microbiological properties in an eroded soil.
Technical Abstract: An experiment was initiated in 2005 at Plant Material Center, NRCS, in Coffeeville Mississippi, on a degraded Loring silt loam (fine-silty, mixed, thermic, Glossic Fragiudalf) soil to determine restorative potential of broiler litter, soil and crop management on selected soil physical, chemical, and biological properties. Treatments include a tillage variable (till vs no-till) and broiler litter at the rate of 0, 9, and 18 Mg ha-1 applied every other year to corn followed by winter wheat for grain. Changes in soil physical, chemical, and biological properties as well as grain yield were evaluated every year. The results indicated soil pH in the surface 0-7.5 cm depth increased with increasing broiler litter rate ranging from 4.1 for the control to 5.6 for the highest broiler rate of 18 Mg ha-1. The addition of broiler litter at the highest rate (18 Mg ha-1) increased soil total C and N concentrations by 61 and 53% and soil P content by 7 fold (from 4.6 to 32.2 mg kg-1). Soil bulk density was reduced by 10% (from 1.39 to 1.26 g cm-3) and hydraulic conductivity increased by 2.4 fold (from 3.6 to 8.6 cm h-1) with broiler litter application. Increasing soil physical indicator values most likely attributed to increasing soil organic matter resulted from broiler litter application and cropping systems. In addition, corn and wheat grain yield increased with increasing broiler litter application and the results were greater under the deep tillage than no-till system. This indicates that application of poultry manure along with tillage systems can be a good method for restoring the quality and productivity of degraded land.